1. Field of the Invention
The present invention relates to tracer-containing chemical compositions. The present invention further relates to a process for using perfluorocarbon tracers in such compositions as a means of determining the possible adulteration of chemical compositions by identifying and quantitatively determining the amounts of such tracers present in such compositions.
2. Description of the Prior Art
The petrochemical industry has traditionally been faced with the problem of distinctively characterizing products for identification purposes. This characterization has typically been accomplished by using various labels or tags. Chlorohydrocarbons have been used to tag hydrocarbon fuel compositions but require that large amounts, from 0.01 mg/l to 10 mg/l, be incorporated for detection. See U.S. Pat. No. 4,141,692. Chlorofluorocarbons, which offer the advantage of having a lower limit of detection, have also been used as tracers. Both chlorohydrocarbons and chlorofluorocarbons are unacceptable though since each is known to deplete the ozone.
Dyes have also been used to tag products such as gasolines, but have proven ineffective for tagging products with a high degree of color. In addition, dyes generally have a high boiling point which makes them unsuitable for many applications.
Radioactive materials function as effective tags since they are detected using noninvasive procedures. Although isotopically labelled compounds are commercially available, the quantity of tracer needed makes them cost prohibitive. In addition, such materials cannot be readily used in commercial products.
It has now been found that very small amounts of one or more perfluorocarbon compounds can be used as tags in chemical compositions to unambiguously identify such compositions and to quantitatively determine the amounts of such tracers in admixture with other materials.